merge substrate-bn branch into master (#21)

* fix edition and prepare publish

* Publish for substrate branch

* fix edition 2018

* add Parity as authors

Co-authored-by: NikVolf <nikvolf@gmail.com>

examples/dh.rs

@@ -1,10 +1,7 @@
 // This is an example of three-party Diffie-Hellman key exchange
 // Requires two rounds
 
-extern crate bn;
-extern crate rand;
-
-use bn::*;
+use substrate_bn::*;
 
 fn main() {
     let rng = &mut rand::thread_rng();

examples/joux.rs

@@ -1,6 +1,4 @@
-extern crate bn;
-extern crate rand;
-use bn::{Group, Fr, G1, G2, pairing};
+use substrate_bn::{Group, Fr, G1, G2, pairing};
 
 fn main() {
     let rng = &mut rand::thread_rng();